Laser Control System and Apparatus for Drilling and Boring Operations

ABSTRACT

A laser control system and apparatus for guiding a drilling or boring operation during a trenchless technology implementation. In most if not all trenchless technology applications, direction of the pipe or utility structure through the earth is of utmost importance. Proper directional guidance throughout the trenchless technology implementation ensures not only that the resulting utility infrastructure is placed properly, but also ensures that the trenchless technology operation does not hit or otherwise damage (such as through vibrations) existing utilities and other underground objects. The laser control system and apparatus of the present invention comprises a laser, a laser control head having a prism, an audible alignment indicator operatively coupled to the laser control head, and a target having a laser beam hole.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the benefit of the filing date of U.S. provisional patent application Ser. No. 60/827,116 filed on Sep. 27, 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to control systems for drilling and boring operations, and more particularly to a laser based control system and apparatus for drilling and boring operations.

2. Description of Related Art

Trenchless technology is a growing field that includes a wide variety of methods and techniques for installing and rehabilitating underground infrastructure with minimal surface disruption and without the destruction and subsequent rebuilding of essential infrastructure that is common with trenching and excavation. Examples of trenchless technologies include, but are not limited to, microtunneling, pipejacking, pipe ramming, sliplining, guided boring, haul systems, tunnel boring, and earth pressure balance systems.

In most if not all trenchless technology applications, direction of the pipe or utility structure through the earth is of utmost importance. Proper directional guidance throughout the trenchless technology implementation ensures not only that the resulting utility infrastructure is placed properly, but also ensures that the trenchless technology operation does not hit or otherwise damage (such as through vibrations) existing utilities and other underground objects.

In some trenchless technology operations such as microtunneling and guided boring, the boring or tunneling tool can be guided during the operation itself by various techniques. In other trenchless technology operations, such as pipejacking and pipe ramming, the method is non-steerable, and pipes installed by these methods are laid straight. Often times a pilot tube is placed prior to the pipejacking or pipe ramming operation using a technique such as microtunneling. The subsequent pipejacking or pipe ramming operation will then follow the pilot tube to ensure that the pipe is installed in it's proper location.

In guiding a trenchless technology operation, knowledge of when the cutting head is deviating from it's intended course is extremely valuable so that the machine operator can make adjustments necessary to bring the direction of the cutting head back on course. The cutting head may deviate from it's intended course for a variety of reasons, such as machine or operator inputs, encounter of different soil types, encounter of a rock or boulder, and the like. Knowing when such a deviation occurs and the extent of such a deviation is important to ensure that timely course corrections are made.

It is an object of the present invention to provide a laser control system and apparatus for drilling and boring operations. It is another object of the present invention to provide a laser control system and apparatus for drilling and boring operations where the control head is low cost in the event of a cutting head malfunction. It is a further object of the present invention to provide a laser control system and apparatus for drilling and boring operations where the control head does not require a power source. It is a further object of the present invention to provide a laser control system and apparatus for drilling and boring operations that is reliable and not susceptible to failure. It is a further object of the present invention to provide a laser control system and apparatus for drilling and boring operations that can optionally be operated remotely.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a laser control system and apparatus for drilling and boring operations comprising a laser, an optical control head, an audible alignment indicator operatively coupled to the optical control head, and a target having a laser beam hole.

The foregoing paragraph has been provided by way of introduction, and is not intended to limit the scope of the present invention as defined by this specification, drawings, and attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by reference to the following drawings, in which like numerals refer to like elements, and in which:

FIG. 1 is a diagram of a laser controlled trenchless operation;

FIG. 2 is a plan view of an optical control head;

FIG. 3 is a perspective view of an optical control head;

FIG. 4 is a perspective view of an audible alignment indicator; and

FIG. 5 is a plan view of a target.

The present invention will be described in connection with a preferred embodiment, however, it will be understood that there is no intent to limit the invention to the embodiment described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by this specification, drawings, and appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements.

FIG. 1 is a diagram of a laser controlled trenchless operation. In a horizontal trenchless operation, it is common to have an insertion pit 101 and a receiving pit 103 that correspond with the origination and the termination of the trenchless operation or a segment thereof. The insertion pit 101 and the receiving pit 103 are typically excavated and often times reinforced for worker safety. If the trenchless operation is performed on a slope, one or both of the insertion pit 101 and the receiving pit 103 may not be necessary. An example of such an application is the trenchless installation of a culvert pipe under a raised railroad bed where trenchless technology is used to prevent settling or disruption of the railroad bed. The raised railroad bed has slopes on either side of the railroad bed that negate the need to excavate an insertion pit 101 or a receiving pit 103. FIG. 1 further shows the top of terrain 105. The laser controlled trenchless operation of FIG. 1 is exemplary only, and is not intended to limit the scope of the present invention to any particular type or method of trenchless technology. A pipe 107 is drilled from the insertion pit 101 to the receiving pit 103. The pipe 107 may be steel or other material suitable to drilling or boring operations, as will be known to those skilled in the art. The pipe 107 may be rotated and driven by a drive unit 109. Examples of such drive units are those units manufactured by Akkerman, Inc. of Brownsdale, Minn., and whose products can be seen at www.ackermnanin.com. The drive unit 109 provides rotation to the pipe 107 as well as horizontal displacement sufficient to progress the drilling or boring operation. At the far end of the pipe 107 is a pipe head 111 that serves to cut through soil as the pipe 107 is rotated and driven by the drive unit 109. In some embodiments of the present invention, tile pipe head 111 is beveled to help guide placement of the pipe 107. An operator can control the yaw and pitch of the pipe 107 as it is being inserted through the ground. This control is performed by slowing or stopping the rotation of the pipe 107 at the drive unit 109 while maintaining or modifying the horizontal force applied to the pipe 107. Due to the geometry of the pipe head 111, the pipe 107 will tend to track on a linear course when rotation is applied from the drive unit 109, and will tend to track in a non-linear fashion when rotation from the drive unit is slowed down or stopped. This attribute is useful in controlling the direction of the pipe 107. Should the pipe 107 deviate from it's intended course during installation, the direction of the pipe 107 can be altered by slowing or stopping the rotation of the pipe 107, orienting the pipe head 111 such that the beveled surface of the pipe head provides non-linear tracking in the intended direction, and then resuming rotation of the pipe 107 once it is determined that the pipe 107 has returned to it's intended course during installation. The laser control system and apparatus of the present invention allows one to determine if the direction of travel of the pipe 107 has deviated from it's intended course during installation, and further, allows one to determine the angular position of the pipe head 111 such that course corrections can be made. The laser control system and apparatus of the present invention uses an optical control head 200 with a prism 201 within the pipe 107 to provide information to an operator regarding the direction of travel of a pipe 107 being installed and the angular position of the pipe head 111. A laser 113 originates a sending beam 117 through a hole in a target 115, through the drive unit 109, and down the length of pipe 107. Upon reaching the prism 201, a returning beam 119 travels down the length of pipe 107 until it strikes a target 115. The prism 201 may be any prism used to redirect light, and in particular laser light. The return beam 119 is oriented with respect to the sending beam 117 based on the angular position of the prism 201 and the attached optical control head 200. It is thus important to know the angular position of the prism 201 and the attached optical control head 200 during the boring s or drilling operation. The target 115 is shown in further detail in FIG. 5, and provides the location of the sending beam 117 by way of a pass through hole and the returning beam 119. The placement of the sending beam 117 with respect to the returning beam 119 provides the operator with information on the deviation of travel of the pipe 107 during installation. This allows the operator to make minor course corrections throughout the installation process. It is important to know the angular position of the optical control head 200 so that the pipe head 111 can be rotated to the proper position to allow for travel in a specified direction. The optical control head 200 contains a signaling mechanism that allows for the determination of angular position of the control head 200. This mechanism will be shown in FIGS. 2, 3, and 4.

It is often times inconvenient or impossible to view the target 115 while operating the drive unit 109. In these situations, an optional video camera 121 is directed at the target 115 and a display unit (not shown) may be placed in a position convenient for the operator or others to view the target 115.

During operation of the laser control system and apparatus of the present invention, the target 115 is continuously monitored during a drilling or boring operation, and minor course deviations are corrected through operator intervention by slowing or stopping the rotation of the pipe 107, orienting the pipe 107 and attached pipe head 111 in an angular position that will allow the pipe head 111 to travel in a direction that will compensate for the detected course deviation, providing horizontal displacement of the pipe 107 and pipe head 111 until such time as the course is corrected, and then returning to rotational and horizontal displacement boring or drilling.

As will become evident to one skilled in the art after reading this specification with the attached drawings and claims, the laser control system and apparatus of the present invention is well suited to a variety of trenchless operations, and also to vertical boring and drilling operations.

Turning now to FIG. 2, a plan view of an optical control head according to one embodiment of the present invention is shown. The prism 201, as previously described, can be seen. The prism 201 is structurally attached to a first flange 203, which is in turn connected to a strut 205 that is in turn connected to a second flange 207. The purpose of the flange and strut arrangement is to provide mechanical integrity to the device and also to provide acoustical isolation for the audible alignment indicator 400. In some embodiments of the present invention, the audible alignment indicator may be electronic, using a position sensing device such as a mercury switch and an electronic device such as a buzzer, horn, bell, or the like. The first flange 203, the strut 205, and the second flange 207 may be made from a metal such as steel, brass, copper, stainless steel, or the like. The first flange 203, the strut 205, and the second flange 207 may also be made from a plastic. The audible alignment indicator 400 is shown in further detail in FIG. 4, and essentially provides an audible signal similar to a bell when the optical control head 200 is placed at an angular position that would indicate 12 o'clock, or another fixed reference point. The audible alignment indicator 400 may be made from a metal such as steel, brass, copper, stainless steel, or the like. A shaft 209 connects the second flange 207 to an expandable plug 211, a tightener 213 and a threaded shaft 215. The shaft 209, the tightener 213 and the threaded shaft 215 may be made from a metal such as steel, brass, copper, stainless steel, or the like. The shaft 209, the tightener 213 and the threaded shaft 215 may also be made from a plastic. The expandable plug 21 may be made from a material such as rubber, silicone, or the like. The purpose of the expandable plug 211, tightener 213 and threaded shaft 215 is to attach the optical control head 200 to the inside of a pipe without allowing for rotation. While the expandable plug 211, tightener 213 and threaded shaft 215 portray a specific embodiment, other attachment means may be used without departing from the spirit and scope of the present invention.

Turning now to FIG. 3, a perspective view of an optical control head according to one embodiment of the present invention is shown. The prism assembly 201 can be seen along with the prism glass 301 and a visual alignment indicator 303. The visual alignment indicator 303, as can be seen in FIG. 3, is a marking that indicates 12 o'clock or another fixed angular position reference. Also shown in FIG. 3 is the first flange 203, the strut 205, and the second flange 207. Also shown is the audible alignment indicator 400.

Turning now to FIG. 4, a perspective view of an audible alignment indicator 400 according to one embodiment of the present invention is shown. The audible alignment indicator 400 has been removed from the optical control head 200 for clarity, and serves to provide an audible indication of a specified angular position. As can be seen in FIG. 4, a striker 401 is attached to a pivot pin 403 and is free to rotate about the pivot pin 403 upon rotation of the audible alignment indicator 400. The pivot pin 403 is offset from the center of the bell housing 409 such that the striker 401 clears the bell housing 409 when rotated 180 degrees, and strikes the bell housing only when rotated a full 360 degrees. This allows for an audible indication only once in a complete 360 degree rotation and also provides the cam-like displacement required for proper operation of the striker 401. In addition, a striker guide plate 405 contains a stop 407 that retains the striker 401 through 90 degrees of rotation and then releases the striker 401 past 90 degrees of rotation such that the striker 401 strikes the bell housing 409 and generates a bell like sound. The components of the audible alignment indicator 400 are preferably a metal such as steel, brass, copper, stainless steel or the like. Plastic materials may also be used for some of the components.

Lastly, FIG. 5 shows a plan view of a target 500 according to one embodiment of the present invention. The target backing 501 may be made of paper, plastic, spunbonded polyolefin wood, steel, aluminum, or any material that is suitable for a planar structure. A laser beam hole 503 is placed through the target 500 to accommodate a sending laser beam as was previously described and portrayed by way of FIG. 1. A laser beam termination 505 may be seen on a target in use. The target further may have angular displacement markings such as the clock indicators 507 to represent 12 o'clock, 509 to represent 3 o'clock, 511 to represent 6 o'clock, and 513 to represent 9 o'clock. Alternatively, other angular displacement indicators in degrees, radians, or the like, may also be used. The position of the laser beam termination 505 in relation to the laser beam hole 503 indicates the deviation distance and direction from course during a boring or drilling operation. The target 500 may also contain a laser sensing device or devices such as an infrared sensor, photo diode, or the like. Further details related to the use of the target 500 with the laser control system and apparatus of the present invention have been previously provided in this specification.

It is, therefore, apparent that there has been provided, in accordance with the various objects of the present invention, a laser control system and apparatus for drilling and boring operations. While the various objects of this invention have been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of this specification, drawings, and appended claims. 

1. An optical control head for drilling and boring operations comprising: a prism assembly having a prism, the prism assembly being connected to a shaft; a first flange operatively coupled to said shaft; an audible alignment indicator operatively coupled to said shaft; and a second flange operatively coupled to said shaft.
 2. The optical control head as recited in claim 1, further comprising an expandable plug connected to said shall.
 3. The optical control head as recited in claim 1, further comprising a tightener connected to said shaft.
 4. The optical control head as recited in claim 1, wherein said audible alignment indicator comprises a bell housing and a striker.
 5. The optical control head as recited in claim 1, wherein said audible alignment indicator comprises a bell housing, a striker, a pivot pin and a stop.
 6. The optical control head as recited in claim 1, wherein said audible alignment indicator is electronic.
 7. The optical control head as recited in claim 1, further comprising a strut connected to said first flange and said second flange.
 8. The optical control head as recited in claim 1, wherein said prism has a visual alignment indicator marking.
 9. A target for drilling and boring operations comprising: a target backing; a laser beam hole made in the target backing; and angular displacement markings made on the target backing.
 10. The target for drilling and boring operations as recited in claim 9 further comprising a laser beam termination.
 11. The target for drilling and boring operations as recited in claim 9, wherein said angular displacement markings are clock indicators.
 12. The target for drilling and boring operations as recited in claim 9, wherein said angular displacement markings are in degrees.
 13. Tile target for drilling and boring operations as recited in claim 9, wherein said angular displacement markings are in radians.
 14. The target for drilling and boring operations as recited in claim 9 further comprising a laser beam sensor.
 15. A laser control system for drilling and boring operations comprising: a laser; an optical control heady; an audible alignment indicator operatively coupled to the optical control head; and a target having a laser beam hole.
 16. The laser control system for drilling and boring operations as recited in claim 15, further comprising a pipe operatively coupled to said optical control head.
 17. The laser control system for drilling and boring operations as recited in claim 15, is further comprising a prism operatively coupled to said optical control head.
 18. The laser control system for drilling and boring operations as recited in claim 17, wherein said prism has a visual alignment indicator marking.
 19. The laser control system for drilling and boring operations as recited in claim 15, wherein said audible alignment indicator is mechanical.
 20. The laser control system for drilling and boring operations as recited in claim 15, wherein said audible alignment indicator is electronic. 